The evaluation and treatment of depression is an important component of the management of individuals with Parkinson’s disease. This review summarises current knowledge on the epidemiology, pathophysiology and treatment of depression in Parkinson’s disease. Limited information is available regarding the pathophysiology of depression in Parkinson’s disease and the effectiveness of treatment. Selective serotonin (5-hydroxytryptamine; 5-HT) reuptake inhibitors (SSRIs) are commonly used but more information is needed regarding their tolerability and antidepressant efficacy in patients with Parkinson’s disease, and their effect on motor function. Antidepressants can interact with selegiline (deprenyl) to cause the ‘serotonin syndrome’, although retrospective chart reviews indicate that this is rare. While several case reports have noted worsening parkinsonian motor features with SSRI use, open-label prospective studies have not substantiated these findings. Further double-blind, prospective studies would be valuable to further evaluate the tolerability and efficacy of antidepressants in Parkinson’s disease.